Gas Optimizations

[code423n4]

[N-01] Adding a return statement when the function defines a named return variable, is redundant:-

  1. File: 2022-07-swivel/Marketplace/MarketPlace.sol (line 207):

      `return interest;`          

  2. File: 2022-07-swivel/Marketplace/MarketPlace.sol (line 166):

      `return (amount);`

  3. File: 2022-07-swivel/Swivel/Hash.sol (line 74):

      `return hash;`

[N-02] constants should be defined rather than using magic numbers:-

  1. File: 2022-07-swivel/Creator/VaultTracker.sol (line 224-227):

      `yield = ((maturityRate * 1e26) / sVault.exchangeRate) - 1e26;
  } else {
      yield = ((exchangeRate * 1e26) / sVault.exchangeRate) - 1e26;
  }`          

  2. File: 2022-07-swivel/Marketplace/FixedPointMathLib.sol (line 61):

      `int256 k = ((x << 96) / 54916777467707473351141471128 + 2**95) >> 96;`

  3. File: 2022-07-swivel/Marketplace/FixedPointMathLib.sol (line 56):

      `x = (x << 78) / 5**18;`

[N-03] Use a solidity version of at least 0.8.12 to get string.concat() to be used instead of abi.encodePacked(<str>,<str>):-

  1. File: 2022-07-swivel/Creator/Erc20.sol (line 4):

      `pragma solidity ^0.8.0;`          

  2. File: 2022-07-swivel/Marketplace/Erc20.sol (line 4):

      `pragma solidity ^0.8.0;`

  3. File: 2022-07-swivel/Tokens/FixedPointMathLib.sol (line 2):

      `pragma solidity ^0.8.0;`

[N-04] Use a solidity version of at least 0.8.12 to get string.concat() to be used instead of abi.encodePacked(<str>,<str>):-

  1. File: 2022-07-swivel/Creator/Erc20.sol (line 15-17):

      `  event Transfer(address indexed from, address indexed to, uint256 amount);

event Approval(address indexed owner, address indexed spender, uint256 amount);`          

  2. File: 2022-07-swivel/Creator/IERC5095.sol (line 6):

      `event Redeem(address indexed from, address indexed to, uint256 amount);`

  3. File: 2022-07-swivel/Creator/Interfaces.sol (line 20-21):

      `event Transfer(address indexed from, address indexed to, uint256 value);

event Approval(address indexed owner, address indexed spender, uint256 value);`

  4. File: 2022-07-swivel/Marketplace/Erc20.sol (line 15-17):

      ` event Transfer(address indexed from, address indexed to, uint256 amount);

event Approval(address indexed owner, address indexed spender, uint256 amount);`          

  5. File: 2022-07-swivel/Creator/IERC5095.sol (line 6-7):

      `event Transfer(address indexed from, address indexed to, uint256 value);

event Approval(address indexed owner, address indexed spender, uint256 value);`

  6. File: 2022-07-swivel/Tokens/IERC5095.sol (line 6):

      `event Redeem(address indexed from, address indexed to, uint256 amount);`  

  7. File: 2022-07-swivel/Tokens/Interfaces.sol (line 20-21):

      `  event Transfer(address indexed from, address indexed to, uint256 value);

event Approval(address indexed owner, address indexed spender, uint256 value);`

  8. File: 2022-07-swivel/VaultTracker/Interfaces.sol (line 20-21):

      `event Transfer(address indexed from, address indexed to, uint256 value);

event Approval(address indexed owner, address indexed spender, uint256 value);`

[N-05] Missing checks for address(0x0) when assigning values to address state variables:-

  1. File: 2022-07-swivel/Creator/VaultTracker.sol (line 35-36):

      `cTokenAddr = c;
swivel = s;`          

[kartoonjoy]

Per warden, this issue needs to be withdrawn so they can resubmit properly.